Success Criterion 2.5.4
Conformance level A

Motion Input Triggered Accidentally by Hand Tremors

2.5.4 — Motion Actuation

Scenario

Setting

A photo-sharing app's upload screen

What’s wrong

Motion input that can be triggered accidentally (tremor) with no setting to turn it off.

Example

window.addEventListener('devicemotion', undoLastAction); // shake-only

Why it matters

People with tremor and people whose device cannot be moved freely.

How to test

Hold the device with a slight natural tremor: if the motion feature triggers accidentally with no setting to turn it off, it fails.

How to fix

A conventional on-screen control must duplicate the motion-triggered feature, and motion input must be able to be turned off. window.addEventListener('devicemotion', undoLastAction); // plus a visible Undo button doing the same thing Motion-triggered actions need a standard UI control alternative, and a way to turn motion actuation off.

Outcome

On a photo-sharing app's upload screen, this barrier is gone for people with tremor and people whose device cannot be moved freely — they get the same result as anyone else here.

Who is affected